The Unconditional Spanish Party (Spanish: Partido Incondicional Español) was a loyalist conservative political party in Puerto Rico. It was founded on November 1870 as the Liberal-Conservative Party but in 1873 it changed its name to Unconditional Spanish Party. The party favored traditionalist assimilation into the political party system of Spain. It purchased the newspaper Boletín Mercantil to serve as the party's official organ for disseminating its conservative views. Most of its members belonged to the Puerto Rican Volunteers Corps.